Since the 1930s, rollers have been utilized for applying paint and other coatings to walls, ceilings, floors, and other surfaces. Typically, a roller includes two components, in the form of a handle assembly and a roller cover for installation onto the handle assembly. The handle assembly typically consists of a grip element having a generally L-shaped metal frame extending therefrom, with the free end of the metal frame having a rotatable support for the roller cover to be mounted thereon. The roller cover typically consists of a thin, hollow cylindrical core which fits onto the rotatable support of the handle, with a plush pile fabric being secured to the outer periphery of the roller cover. The core may be made of any appropriate material, such as cardboard or plastic. The pile fabric has traditionally been applied as a strip of fabric which is helically wound onto the outer surface of the core, with adjacent windings of the fabric strip being located as closely adjacent as possible to each other to provide the appearance of a single continuous pile fabric covering on the core.
The use of helically wound strips to provide the pile on roller covers is undesirable because, even where great care is taken in precisely cutting and winding the strips of fabric onto the core, the resulting juncture between two adjacent strips still sometimes results in noticeable marks being left on the surface being painted or otherwise coated by the roller cover. Even where the resulting juncture is initially carefully made, the pile fibers along the sides of the juncture are sometimes lost during use of the roller cover, as a result of the fabric being cut into strips. The precise cutting and winding operations required to produce a roller cover giving satisfactory performance can substantially increase the cost of manufacturing a roller cover.
The use of helically wound coverings on prior rollers has been necessary primarily due to the fact that the pile fabrics suitable for use as roller coverings could only be knitted in a tubular form having large diameters, such as 24 inches for example, having a circumference far larger than the outer periphery of the core of a typical roller. These large diameter knitted fabrics were then slit to form a flat sheet of fabric having a pile extending from one surface thereof. The large sheet of fabric was then cut into strips for winding about the core to form the completed roller.
For the most popular type of knitted fabric for roller covers, having a pile formed from small tufts, known as slivers, of fabric knitted into a knitted backing, another drawback existed in prior methods and apparatuses which were only capable of producing tubular-shaped knitted coverings having the pile extending from an inner surface of the tubular-shaped length of knitted covering. As a result, even if the tubular-shaped covering could have been produced in a diameter small enough to be simply slipped over the core of a roller, it would have been necessary to first turn the entire length of tubular knitted covering inside-out in order to move the pile from the inside to the outside of the tube of fabric.
In a commonly assigned U.S. patent application bearing Ser. No. 11/740,119, titled “Tubular Sliver Knit Fabric For Paint Roller Covers,” the disclosure and teachings of which are incorporated herein in their entireties by reference, the inventor of the present invention discloses a tubular sliver knit fabric for a roller cover having the pile extending from the outer surface of the knitted fabric and an inner diameter defined by the base fabric which is small enough in diameter to be slipped over the core of a roller, thereby eliminating the operations of cutting and helically winding strips of fabric onto a core as was required for fabrication of prior roller covers.
It is desirable, therefore, to provide an improved method and apparatus for knitting material having a pile extending therefrom, in a form which is more amendable for use as a covering for a core of a paint roller. It is also desirable to provide an improved method and apparatus for knitting the covering of a roller without having to resort to the traditional practice of helically winding strips of the knitted fabric onto a core. It is particularly desirable to provide a method and apparatus for knitting the covering of a roller in accordance with the inventor's commonly assigned U.S. patent application Ser. No. 11/740,119 referenced above.